This invention relates to a method of stimulating the immune system of a warm-blooded animal by the production of antibodies.
It is well-known that warm-blooded animals have several types of cells which constitute various lines of defense of the body against the invasion of foreign agents. One line of defense involves the leukocytes and macrophages in the blood stream which are capable of phagocytizing the foreign agent and often destroying it when such cells come in contact with the foreign agent.
Another line of defense involves an immune mechanism which is brought into action by the antigenic constituent of the foreign agent. One type of immune mechanism involves the B-cells which are precursors of cells that secrete immunoglobulins (Igs) or antibodies. The immunoglobulins or antibodies play a significant role in the fight against infection caused by bacteria or other infectious microorganisms.
Consequently, methods of stimulating the immune system to produce antibodies are useful for immune-deficient patients.
It is known that different B-cell mitogens stimulate secretion of distinctive patterns of immunoglobulin classes and subclasses in murine systems. For example, lipopolysaccharides (LPS) stimulate IgM, IgA, IgG3 and IgG2b; Corynebacterium parvum stimulates IgM, IgA, IgG1 and IgG3; and pokeweed mitogen stimulates IgM, IgA, IgG1, IgG2a, IgG2b and IgG3.
Bacterial endotoxins are complex molecules that contain lipopolysaccharides. Although these endotoxins can stimulate antibody production, they exhibit extreme toxicity which appears to reside in their lipid fraction. When injected in sufficient amounts, they usually cause irreversible shock within an hour our two.